Huang Shilin, Brown Kenneth R, Cetina Marko
Duke Quantum Center, Duke University, Durham, NC 27701, USA.
Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA.
Sci Adv. 2024 Nov 8;10(45):eadp2008. doi: 10.1126/sciadv.adp2008. Epub 2024 Nov 6.
Quantum states decohere through interaction with the environment. Quantum error correction can preserve coherence through active feedback wherein quantum information is encoded into a logical state with a high degree of symmetry. Perturbations are detected by measuring the symmetries of the state and corrected by applying gates based on these measurements. To measure the symmetries without perturbing the data, ancillary quantum states are required. Shor error correction uses a separate quantum state for the measurement of each symmetry. Steane error correction maps the perturbations onto a logical ancilla qubit, which is then measured to check several symmetries simultaneously. We experimentally compare Shor and Steane correction of bit flip errors using the Bacon-Shor code implemented in a chain of 23 trapped atomic ions. We find that the Steane method produces fewer errors after a single round of error correction and less disturbance to the data qubits without error correction.
量子态通过与环境的相互作用而退相干。量子纠错可以通过主动反馈来保持相干性，其中量子信息被编码到具有高度对称性的逻辑态中。通过测量状态的对称性来检测扰动，并基于这些测量应用门操作来进行校正。为了在不干扰数据的情况下测量对称性，需要辅助量子态。Shor纠错为每个对称性的测量使用一个单独的量子态。Steane纠错将扰动映射到一个逻辑辅助量子比特上，然后对其进行测量以同时检查多个对称性。我们使用在23个俘获原子离子链中实现的Bacon-Shor码，通过实验比较了Shor和Steane对比特翻转错误的校正。我们发现，在单轮纠错后，Steane方法产生的错误更少，并且对未纠错的数据量子比特的干扰也更小。
